Lipopolysaccharide stimulates endogenous β-glucuronidase via PKC/NF-κB/c-myc signaling cascade: a possible factor in hepatolithiasis formation

VOC-Based Probes, a New Set of Analytical Tools to Monitor Patient Health from Blood Sample. Proof of Concept on Tracking COVID-19 Infection

Induced volatolomics is an emerging field that holds promise for many biomedical applications including disease detection and prognosis. In this pilot study, we report the first use of a cocktail of volatile organic compounds (VOCs)-based probes to highlight new metabolic markers allowing disease prognosis. In this pilot study, we specifically targeted a set of circulating glycosidases whose activities could be associated with critical COVID-19 illness. Starting from blood sample collection, our approach relies on the incubation of VOC-based probes in plasma samples. Once activated, the probes released a set of VOCs in the sample headspace. The dynamic monitoring of the signals of VOC tracers enabled the identification of three dysregulated glycosidases in the initial phase after infection, for which preliminary machine learning analyses suggested an ability to anticipate critical disease development. This study demonstrates that our VOC-based probes are a new set of analytical tools that can provide access to biological signals until now unavailable to biologists and clinicians and which could be included in biomedical research to properly construct multifactorial therapy algorithms, necessary for personalized medicine.

Mechanistic Understanding of D-Glucaric Acid to Support Liver Detoxification Essential to Muscle Health Using a Computational Systems Biology Approach

Liver and muscle health are intimately connected. Nutritional strategies that support liver detoxification are beneficial to muscle recovery. Computational-in silico-molecular systems' biology analysis of supplementation of calcium and potassium glucarate salts and their metabolite D-glucaric acid (GA) reveals their positive effect on mitigation of liver detoxification via four specific molecular pathways: (1) ROS production, (2) deconjugation, (3) apoptosis of hepatocytes, and (4) β-glucuronidase synthesis. GA improves liver detoxification by downregulating hepatocyte apoptosis, reducing glucuronide deconjugates levels, reducing ROS production, and inhibiting β-Glucuronidase enzyme that reduces re-absorption of toxins in hepatocytes. Results from this in silico study provide an integrative molecular mechanistic systems explanation for the mitigation of liver toxicity by GA.

Macrophages and derived-TNF-α promote lipopolysaccharide-induced upregulation of endogenous β-glucuronidase in the epithelial cells of the bile duct: A possible facilitator of hepatolithiasis formation

BACKGROUND

Hepatolithiasis is prevalent in Southeast Asian regions, and the role of endogenous β-glucuronidase (β-GD) in the formation of hepatolithiasis is being gradually recognised. Revealing the regulation mechanism of the expression of endogenous β-GD will provide new therapeutic strategies for intervening in the formation of hepatolithiasis.

METHODS

Liver specimens from patients with hepatolithiasis were examined by immunohistochemistry to assess the expression of macrophage markers including CD68, CD80, and CD206, as well as that of TNF-α and endogenous β-GD, compared with that in normal liver samples. HiBEpiC cells were co-cultured directly or indirectly with induced M2 macrophages or directly stimulated with TNF-α, and the expression of the endogenous β-GD was examined. A PKC inhibitor, chelerythrine, and an NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), were used to elucidate the possible regulation mechanism.

RESULTS

The expression of macrophage markers including CD68 and CD206, as well as that of TNF-α and endogenous β-GD significantly increased in liver specimens from patients with hepatolithiasis compared with that in normal liver samples. The expression of CD68, CD206 and TNF-α was positively correlated with that of endogenous β-GD. When HiBEpiC cells were co-cultured directly or indirectly with M2 macrophages, following stimulation with lipopolysaccharide (LPS), the expression of endogenous β-GD was significantly higher in the indirect co-culture group than that in the direct co-culture group, or in HiBEpiC cells or M2 macrophages cultured alone. Further experiments revealed that following stimulation with LPS, TNF-α secretion increased in both the indirect and direct co-culture groups compared with that in HiBEpiC cells cultured alone. TNF-α increased the expression of endogenous β-GD in HiBEpiC cells, in a dose- and time-dependent manner. In addition, TNF-α significantly increased the expression levels of p-P65 and proliferating cell nuclear antigen (PCNA), and PDTC effectively inhibited the TNF-α-induced expression of PCNA and β-GD.

CONCLUSIONS

Infiltration of macrophages, especially M2 macrophages, may be involved in the hepatolithiasis formation. LPS activates the macrophages, inducing the secretion of TNF-α, which can further increase the expression of endogenous β-GD in the epithelial cells of the bile duct, possibly via the NF-κB/PCNA signalling cascade.

The Sphingosine Kinase 2 Inhibitor Opaganib Protects Against Acute Kidney Injury in Mice

Introduction

Acute kidney injury (AKI) is a common multifactorial adverse effect of surgery, circulatory obstruction, sepsis or drug/toxin exposure that often results in morbidity and mortality. Sphingolipid metabolism is a critical regulator of cell survival and pathologic inflammation processes involved in AKI. Opaganib (also known as ABC294640) is a first-in-class experimental drug targeting sphingolipid metabolism that reduces the production and activity of inflammatory cytokines and, therefore, may be effective to prevent and treat AKI.

Methods

Murine models of AKI were used to assess the in vivo efficacy of opaganib including ischemia-reperfusion (IR) injury induced by either transient bilateral occlusion of renal blood flow (a moderate model) or nephrectomy followed immediately by occlusion of the contralateral kidney (a severe model) and lipopolysaccharide (LPS)-induced sepsis. Biochemical and histologic assays were used to quantify the effects of oral opaganib treatment on renal damage in these models.

Results

Opaganib suppressed the elevations of creatinine and blood urea nitrogen (BUN), as well as granulocyte infiltration into the kidneys, of mice that experienced moderate IR from transient bilateral ligation. Opaganib also markedly decreased these parameters and completely prevented mortality in the severe renal IR model. Additionally, opaganib blunted the elevations of BUN, creatinine and inflammatory cytokines following exposure to LPS.

Conclusion

The data support the hypotheses that sphingolipid metabolism is a key mediator of renal inflammatory damage following IR injury and sepsis, and that this can be suppressed by opaganib. Because opaganib has already undergone clinical testing in other diseases (cancer and Covid-19), the present studies support conducting clinical trials with this drug with surgical or septic patients at risk for AKI.

High-fidelity imaging of lysosomal enzyme through in situ ordered assembly of small molecular fluorescent probes

As an organelle in cells, lysosomes play an important role in the degradation of biological macromolecules and pathogens. To elucidate the function of lysosomes in normal or disease states, recently, various fluorescent probes have been reported for imaging lysosomal analytes. However, because of the particularity of the lysosomal environment, most of the reported lysosomal fluorescent probes suffered from a series of practical issues such as easy diffusion, low detection signal-to-background ratio and false signal. To address these issues, based on an optimized in situ ordered assembly solid-state fluorophore HDPQ, we herein put forward a new strategy for the design of lysosomal enzymes probes. As a proof concept, we synthesized a fluorescent probe HDPQ-GLU for lysosomal enzyme β-glucuronidase (GLU). Experiment results displayed that compared with general lysosomal probe, the novel lysosomal probe not only exhibited excellent anti-pH interference ability and high signal-to-noise ratio in aqueous solution, but also has excellent long-term in situ imaging ability in the living system. Using this probe, we have realized high-fidelity and long-term in situ tracking GLU in lysosomes of living cells and evaluated the dynamic changes of GLU during the growth period of zebrafish. We anticipate that the new strategy based on the novel in situ ordered assembly solid-state fluorophore HDPQ may be a potential platform for developing fluorescent probes for high-fidelity imaging of lysosomal enzymes.

Relationship between the risk of idiosyncratic drug toxicity and formation and degradation profiles of acyl-glucuronide metabolites of nonsteroidal anti-inflammatory drugs in rat liver microsomes

Acyl glucuronides (AGs) are considered to cause idiosyncratic drug toxicity (IDT), and evaluating the chemical instability of AGs may be useful for predicting the IDT risk of novel drug candidates. However, AGs show variations in their chemical instability, degree of formation, and enzymatic hydrolysis. Therefore, we evaluated the degree of AG formation, enzymatic hydrolysis, and chemical instability in liver microsomes and their relationship with IDT risk. Nonsteroidal anti-inflammatory drugs (NSAIDs) were classified into three categories in terms of their IDT risk as parent drugs: safe (SA), warning (WA), and withdrawn (WDN). To evaluate the enzymatic and non-enzymatic degradation of AG, the parent drugs were incubated with rat liver microsomes in the absence or presence of AG hydrolase inhibitors. The degree of AG formation and disappearance was considered as the rate constant. For all NSAIDs investigated, the number of AGs formed notably increased following addition of AG hydrolase inhibitors. Particularly, AG was produced by WDN drugs at a lower level than that produced by WA and SA drugs in the absence of AG hydrolase inhibitors but was significantly increased after adding AG hydrolase inhibitors. The rate constants of AG formation and non-enzymatic AG disappearance did not significantly differ among the WDN, WA, and SA drugs, whereas the rate constant of enzymatic AG disappearance of WDN drugs tended to be higher than those of WA and SA drugs. In conclusion, we evaluated the enzymatic degradation and chemical instability of AG by simultaneously producing it in liver microsomes. This method enables evaluation of AG degradation without preparing AG. Moreover, we determined the relationship between enzymatic AG degradation in rat liver microsomes and IDT risk.

Biliary Microbiota in Choledocholithiasis and Correlation With Duodenal Microbiota

Background

The pathogenesis of choledocholithiasis is closely related to the role of bacteria. However, little is known about the predictive role of bile bacteria in clinical conditions of patients and the compositional and functional characteristics of biliary microbiota in choledocholithiasis.

Methods

To investigate the predictive value of biliary bacteria, clinical data of 488 patients with choledocholithiasis were collected. The predictive value of common bile bacteria to patients’ clinical conditions was analyzed by logistic regression. Samples of bile and corresponding duodenal juice from 10 selected patients with choledocholithiasis were obtained, and the composition and function of microbial communities were analyzed based on 16S rRNA sequencing and Tax4Fun.

Results

The clinical conditions of patients with choledocholithiasis, such as recurrence, the severity of acute cholangitis, and duration of hospital stay were closely related to different species of bile bacteria as well as antimicrobial-resistant bacteria. Employing 16S rRNA sequencing, the dominant phyla of biliary and duodenal microbiota were Proteobacteria and Firmicutes. The top three core microbiota at the genus level were Escherichia–Shigella, Fusobacterium, and Enterococcus. Escherichia coli accounted for the most abundant annotated species in both. Differences in composition between biliary and duodenal microbiota were not significant according to the alpha and beta diversities. Differential abundant features were not found in biliary microbiota indicated by A linear discriminant analysis effective size algorithm. The major pathways identified in biliary and duodenal microbiota were related to membrane transport, translation, replication and repair, carbohydrate and amino acid metabolism. However, no significant difference in those major pathways, as well as antimicrobial-resistance patterns, was observed between biliary and duodenal microbiota.

Conclusion

Our study first demonstrates the predictive contribution of biliary bacteria to the clinical conditions of patients with choledocholithiasis, and then it offers new insights into the compositional and functional features of biliary and duodenal microbiota. Similarities between biliary and duodenal microbiota support the theory of bacterial duodenal–biliary reflux in patients with choledocholithiasis. Meanwhile, when it is impracticable to obtain a bile sample, duodenal juice may be used as an alternative for bacterial culture and susceptibility tests.

Biliary antibiotics irrigation for E. coli-induced chronic proliferative cholangitis and hepatolithiasis: A pathophysiological study in rabbits

BACKGROUND

The gram-negative bacteria secreted endotoxin, Lipopolysaccharide (LPS), plays important roles in the formation and recurrence of hepatolithiasis and chronic biliary inflammation in patients of Southeast Asia. We aimed to elucidate the anti-inflammatory effect and mechanism of local antibiotics irrigation on chronic proliferative cholangitis (CPC) and hepatolithiasis.

METHODS

Escherichia coli was injected into rabbit bile ducts to induce CPC. Rabbits were divided into sham operation (SO), povidone-iodine, Metronidazole plus chlorhexidine, ofloxacin, furacillin, Neosporin® G.U., and CPC groups. Local irrigation was performed for 28 days after CPC was established. Residual E. coli and LPS, and the expression of MCP-1, CD14, COX-2, VEGF, IL-6, NF-κB, TNF-α, Fas, TGF-β1, α-SMA, Collagen-I, β-glucuronidase, PKC, C-myc, and Mucin 5AC were assessed in bile duct tissues.

RESULTS

The residual E. coli and LPS, and expression of MCP-1, CD14, COX-2, IL-6, NF-κB, TNF-α, Fas, TGF-β1, α-SMA, β-glucuronidase, PKC, C-myc, and Mucin 5AC in the SO, povidone-iodine, Metronidazole plus chlorhexidine, ofloxacin, and Neosporin® G.U. groups were significantly lower than those in the furacillin and CPC groups (P<0.05). VEGF and Collagen-I levels in the SO, povidone-iodine, metronidazole plus chlorhexidine, and ofloxacin groups were significantly lower than those in the furacillin, Neosporin® G.U., and CPC groups (P<0.05).

CONCLUSIONS

LPS affects the pathophysiology of E. coli caused chronic proliferative cholangitis and hepatolithiasis recurrence. Local antibiotics irrigation could prevent chronic proliferative cholangitis and stones formation by decreasing LPS-induced proinflammatory and profibrotic cytokines release. Povidone iodine, metronidazole plus chlorhexidine, and ofloxacin were more effective than Neosporin® G.U. and furacillin.

Melatonin and alcohol-related disorders

This review concerns the current knowledge of melatonin and alcohol-related disorders. Chronobiological effects of ethanol are related to melatonin suppression and in relation to inflammation, stress, free radical scavenging, autophagy and cancer risk. It is postulated that both alcohol- and inflammation-induced production of reactive oxygen species (ROS) alters cell membrane properties leading to tissue dysfunction and, subsequent further ROS production. Lysosomal enzymes are often used to assess the relationships between intensified inflammation states caused by alcohol abuse and oxidative stress as well as level of tissue damage estimated by the increased release of cellular enzymes into the extracellular space. Studies have established a link between alcoholism and desynchronosis (circadian disruption). Desynchronosis results from the disorganization of the body's circadian time structure and is an aspect of the pathology of chronic alcohol intoxication. The inflammatory conditions and the activity of lysosomal enzymes in acute alcohol poisoning or chronic alcohol-dependent diseases are in most cases interrelated. Inflammation can increase the activity of lysosomal enzymes, which can be regarded as a marker of lysosomal dysfunction and abnormal cellular integrity. Studies show alcohol toxicity is modulated by the melatonin (Mel) circadian rhythm. This hormone, produced by the pineal gland, is the main regulator of 24 h (sleep-wake cycle) and seasonal biorhythms. Mel exhibits antioxidant properties and may be useful in the prevention of oxidative stress reactions known to be responsible for alcohol-related diseases. Naturally produced Mel and exogenous sources in food can act in free radical reactions and activate the endogenous defense system. Mel plays an important role in the normalization of the post-stress state by its influence on neurotransmitter systems and the synchronization of circadian rhythms. Acting simultaneously on the neuroendocrine and immune systems, Mel optimizes homeostasis and provides protection against stress. Abbreviations: ROS, reactive oxygen species; Mel, melatonin; SRV, resveratrol; NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells; ANT, arylalkylamine-N-acetyltransferase; EC cells, gastrointestinal enterochromaffin cells; MT1, melatonin high-affinity nanomolecular receptor site; MT2, melatonin low-affinity nanomolecular receptor site; ROR/RZR, orphan nuclear retinoid receptors; SOD, superoxide dismutase; CAT, catalase; GPx, glutathione peroxidase; GR, glutathione reductase; GSH, reduced form of glutathione; GSSG, oxidized form of glutathione; TAC, total antioxidant capacity; ONOO∙^-, peroxynitrite radical; NCAM, neural cell adhesion molecules; LPO, lipid peroxidation; α-KG, α-ketoglutarate, HIF-1α, Hypoxia-inducible factor 1-α, IL-2, interleukin-2; HPA axis, hypothalamic-pituitary-adrenal axis; Tph1, tryptophan hydroxylase 1; AA-NAT, arylalkylamine-N-acetyltransferase; AS-MT, acetylserotonin O-methyltransferase; NAG, N-acetyl-beta-D-glucosaminidase; HBA1c glycated hemoglobin; LPS, lipopolysaccharide; AAP, alanyl-aminopeptidase; β-GR, β-glucuronidase; β-GD, β-galactosidase; LAP, leucine aminopeptidase.

Management of Hepatolithiasis: Review of the Literature

PURPOSE OF REVIEW

Hepatolithiasis is a disease characterized by intrahepatic stone formation. In this article, we review the features of this disease and explore the established and emerging treatment modalities.

RECENT FINDINGS

Recent reports show an increasing prevalence of hepatolithiasis, likely owed to increased immigration and shifts in the Western diet. New pharmacotherapy options are limited and are often only supportive. Endoscopic intervention still cruxes on removal of impacted stones, though new techniques such as bile duct exploratory lithotomy and lithotripsy continue to advance management. Although hepatectomy of the effected portion of the liver offers definitive therapy, alternative less invasive modalities such as combined endoscopic/interventional radiology modalities have been utilized in select patients. Additionally, liver transplant serves as an option for otherwise incurable hepatolithiasis with coexisting liver dysfunction. Multiple emerging pharmacologic and procedural interventions may provide novel treatment for hepatolithiasis. While definitive therapy remains resection of affected liver segments, these modalities offer hope for less invasive approaches in the future.